There are more than 1,000 bunkers scattered about the Straits course at Whistling Straits, so many that not even the maintenance staff has counted them all.

Perhaps it was fitting that only one – a wispy patch of sand trampled by spectators through a tumultuous Sunday – played a pivotal role in determining a bittersweet and historic chapter in the 92nd PGA Championship.

Germany's Martin Kaymer emerged victorious from a three-hole playoff with Bubba Watson, posting a winning even-par total in the overtime drama to become his country's first PGA Champion and second ever to win one of golf's four majors.

The dramatics, however, were more compelling prior to the playoff when Dustin Johnson – clinging to a one-stroke lead standing on the 18th tee – saw his chances for glory erased due to a rule violation in that tiny sand bunker on the right-hand side of the fairway.

Johnson had placed his 4-iron behind the ball, unaware that it was part of a bunker. He went on to make a brilliant pitch shot to seven feet of the hole, just missing a par putt that was to have been a seemingly Championship-winning stroke.

"It never crossed my mind that I was in a sand trap," said Johnson, who admitted later that he had not read the posted Local Rule regarding bunkers that was in play for the week.

The resulting two-stroke penalty for grounding his club in a bunker – outside the ropes - converted a thrilling final hour into a finish that will be debated for years.

"It was very tough to see what is a bunker and what is not a bunker," said Kaymer, 25, who won the three-hole playoff over Watson with a par-birdie-bogey finish. "I think it's very sad he got two penalty strokes. He played great golf. He's a very nice guy."

Kaymer's first major triumph came amidst a field featuring 97 of the top 100 world-ranked players and a PGA Championship-record 73 players representing 22 countries. He accomplished his feat at Whistling Straits after tying for eighth in the U.S. Open and sharing seventh at the Open Championship.

"I still don't realize what just happened," said Kaymer. "I've got goose bumps just talking about it. I hope this is one of many majors I'll win in my career. I cannot win anything bigger. This gives me huge confidence."

Kaymer (pronounced "Ky-mer") began the day four strokes behind third-round leader Nick Watney and finished regulation tied with Watson at 11-under-par 277. Johnson would have made it a three-way playoff – a repeat of a trio playing extra holes in 2004 when Vijay Singh captured the Wanamaker Trophy.

The ruling against Johnson stunned Watson and Kaymer.

"Very heartbreaking," said Watson, who closed with a 4-under-par 68. "He played great golf and just made a mistake. Going to the playoff without him didn't seem right."

Watson birdied the first playoff hole and Kaymer the second. The moment of truth came when Watson went for the green out of thick rough from 206 yards at the 18th, the third playoff hole, and put his ball into Seven Mile Creek, 40 yards short of the green.

"I was hoping for a flier with my 6-iron, but the ball came out dead," Watson said. "I would hit that shot every day. I don't play to lay up."

After seeing what happened to Watson, Kaymer chipped back to the fairway before putting a 7-iron third shot 15 feet from the hole.

Watson took a penalty stroke, then hit into a bunker behind the green. His ensuing shot hit the flagstick but didn't drop, leaving him with a double bogey. Kaymer needed just two putts for bogey and victory. He knew the green speed well, having made a 15-foot par-saving putt on the 72nd hole to land in the playoff.

"I wasn't very calm the last four or five holes, to be honest," said Kaymer, "but I was very, very calm in the playoff. By then, the pressure was gone because the worst I could finish was second."

The final events prior to the playoff harkened back to Roberto de Vicenzo signing for a higher score than he actually made in the 1968 Masters, which kept him out of a playoff against Bob Goalby.

Johnson had no excuses. The peculiar rule about every bunker being treated the same had been posted in the locker room all week. And he offered none when a PGA Rules official stopped him walking off the green and said, "We've got an issue."

His first reaction when told he might have grounded his club in a bunker: "What bunker?"

Johnson didn't even bother going to the TV truck to study the replay. He knew he grounded the club. He just didn't know that he was in the edge of a bunker, figuring it was grass that had been killed under so much foot traffic.

"The only worse thing that could have happened was if I had made the putt on that last hole," Johnson said.

Thinking he had a chance to win, Johnson missed a 7-foot par putt on the 18th to seemingly slip into a three-man playoff. Instead, the two-shot penalty turned his 71 into a 73, and instead of going to a playoff for redemption from his U.S. Open meltdown, Johnson tied for fifth and headed home.

Kaymer leaped to third in the Ryder Cup standings for Europe and moved to a career-best No. 5 in the world. He became the first Continental European since Spain's Jose Maria Olazabal (1999 Masters) to win a major championship.

Watson was only disappointed for a few minutes until learning he had played his way onto the U.S. Ryder Cup team.

For Johnson, this might take far longer to recover from than the U.S. Open, where he had a three-shot lead going into the final round, took triple bogey on the second hole and shot an 82.